How to connect Motorola GM360 RSSI to MMDVM DMR Repeater

It is one of quite useless repeater’s features 🙂 On the Pi-Star dashboard you can read how strong is user’s signal. First of all, you need to connect PIN 15 from Motorola to your relevant MMDVM pin. On this page HERE I shown how to make a cable between Motorola GM360 (and many more models) and MMDVM from BI7JTA. Without that connection the Pi-star dashboard will always show S9+40dB (or so). So I made a connection between Motorola and MMDVM just to find out it actually does not work. It shows all the time S1 (-61dBm) or so. So quick research and I found thet you have to play with values in file /usr/local/etc/RSSI.dat

So to do it, you have to connect to the Pi-Star through SSH and type the following commands:

  • rpi-rw (to make the system writable)
  • cd /usr/local/etc/ (to enter the right catalog)
  • sudo nano RSSI.dat (to edit the file)
  • edit the file
  • Press ctrl-x and y to confirm changes
  • Unfortunately the only one way I found to apply the new settings is to restart Raspberry Pi. But I am sure there is a more professional way – like restarting the process or something.

For example:

I received signal S9+32dB (-61dBm)

It means (see right column in the table below) radio sent a RAW SSI value around 280 to MMDVM, which has been converted to signal S9+32dB (-61dBm)

Just play with settings to see how it works.

Original settings:Settings that work for me:
43 -43
53 -53
63 -63
73 -73
83 -83
93 -93
99 -99
105 -105
111 -111
117 -117
123 -123
129 -129
135 -135
141 -141
175 -137
190 -124
205 -115
220 -110
235 -100
250 -90
265 -80
280 -75
295 -70
310 -65
325 -60
340 -55

Leave a Reply

Your email address will not be published. Required fields are marked *

Change the CAPTCHA codeSpeak the CAPTCHA code

This site uses Akismet to reduce spam. Learn how your comment data is processed.